Smoke and noxious gasses can be very dangerous to occupants during a building fire. As is well known, many fire-related deaths are the result of smoke inhalation. During a fire, or an event where dangerous gases may be present, fumes are likely to travel very quickly through paths that offer little resistance. Paths such as elevator shafts are often well drafted and provide an excellent avenue by which smoke and other dangerous gases can rapidly travel to otherwise unaffected areas of a building. To prevent such a migration of dangerous gases, many devices and assemblies have been designed to limit the dispersal of such fumes by cutting off possible paths or openings. Examples of such devices are smoke screen assemblies disclosed in U.S. Pat. No. 5,383,510, issued Jan. 24, 1995, and U.S. Pat. No. 5,195,594, issued on Mar. 23, 1993, both of which are incorporated herein by reference in their entirety.
Barriers of the types described in the aforementioned patents are often electro-mechanically operated so that a screen is placed in front of an opening upon the detection of smoke, a noxious gas, or dangerous fumes. In normal conditions, power is provided to the barrier system from a main power supply for the deployment of the barrier. In situations that are accompanied by power loss, the barrier system must switch to a back up power supply, such as a battery system or other alternative power source, for deployment of the barrier. The back up power supply adds to the cost and complexity of the barrier system.
In the drawings, the same reference numbers identify identical or substantially similar elements or acts. The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.